1. Field of the Invention
The present invention relates to a probe apparatus for measuring electrical characteristics of a semiconductor device.
2. Description of the Related Art
As is known, a large number of semiconductor devices are formed on a semiconductor wafer by using a high precision photographic transfer technique, and the wafer is incised in units of semiconductor devices. In such a semiconductor device manufacturing process, conventionally, the electrical characteristics of a semiconductor device as a semifinished product are tested and discriminated by using a probe apparatus upon mounting of the semiconductor device on the semiconductor wafer. Only the semiconductor devices that are determined to be non-defective from the result of the testing measurement are sent to the following steps, e.g., packaging, thus improving the productivity.
The probe apparatus has a wafer holding table movable in the X-Y-Z-.theta. directions. A probe card having a large number of probes corresponding to the electrode pads of the semiconductor devices is fixed above the wafer holding table. The semiconductor wafer is set on the wafer holding table, the wafer holding table is driven to bring the electrodes of the semiconductor devices into contact with the probes, and testing measurement is performed through the probes.
In recent years, it has been attempted to perform the testing measurement as described above at a high temperature by providing a temperature control mechanism to the wafer holding table and heating the semiconductor wafer placed on the wafer holding table. In this case, heat from the wafer holding table is transferred to the probe card. Then, the probe card is sometimes deformed to displace the positions of the probes, thus disabling high-precision measurement. As an apparatus to solve this problem, an apparatus disclosed in, e.g., U.S. Pat. No. 5,124,639, is known. In this apparatus, a heating device is provided also to the probe card holding mechanism to preheat the probe card to a temperature similar to that of the semiconductor wafer. In this known apparatus, the heating device is provided to the support means for supporting the intermediate portions of the probes extending obliquely from the probe card. The inclination of the probes is controlled by this heating device, thereby positioning the distal ends of the styluses.
The packing density of the semiconductor devices has been increased recently, and the pitch of electrode pads of the semiconductor devices has been decreased and the number of electrodes pads of the semiconductor devices has been increased. Therefore, as disclosed in Published Unexamined Japanese Patent Application No. 3-224246 a probe card in which probes are arranged substantially vertically has been developed for practical applications to replace the probe card in which probes are arranged obliquely.
In the probe card having the vertical probes, the problem concerning the testing measurement at a high temperature is not solved. Thus, measurement of such vertical probe must be performed at a normal temperature.